Mechanical Engineering Commons^™

Respiratory Compensated Robot For Liver Cancer Treatment: Design, Fabrication, And Benchtop Characterization, Mishek Jair Musa

Graduate Theses and Dissertations

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death in the world. Radiofrequency ablation (RFA) is an effective method for treating tumors less than 5 cm. However, manually placing the RFA needle at the site of the tumor is challenging due to the complicated respiratory induced motion of the liver. This paper presents the design, fabrication, and benchtop characterization of a patient mounted, respiratory compensated robotic needle insertion platform to perform percutaneous needle interventions. The robotic platform consists of a 4-DoF dual-stage cartesian platform used to control the pose of a 1-DoF needle insertion module. The active …

Hobby Grade Lithium-Ion Batteries For Spacecraft Applications: Establishing An Automated Electrical Characteristics Testing Procedure For Flight Acceptance Of Non-Space-Grade Small Secondary Batteries, Braidon Hughes

Graduate Theses and Dissertations

Li-ion batteries are widely used due to the large amount of rechargeable energy they pack into a small, light package. This higher energy density makes Li-ion batteries ideal for small satellite applications, specifically CubeSats. CubeSats have grown in popularity in higher level education due to the National Aeronautics and Space Administration’s implementation of the Cube Satellite Launch Initiative, making it easier and cheaper to conduct small, low orbit missions. Because these CubeSats are occupying the same space as a crewed spacecraft, it is imperative that they are safe. There are numerous reports of Li-ion batteries creating fires that result in …

A Numerical Study Of Water Entry Problems Based On Overset Meshes, Yanni Chang

Mechanical and Aerospace Engineering Dissertations - Archive

A series of numerical experiments carried out on the water entry of circular cylinders are presented in this study. A cylinder was entering into the water with a prescribed inclined angle and velocity. The interface between water and air is tracked by the Piecewise Linear Interface Calculation (PLIC) schemes in conjunction with the Volume of Fluid (VOF) method. PLIC schemes have been extensively employed in the VOF method for interface capturing in numerical simulations of multiphase flows. Dynamic overset meshes, which have been widely used for problems with relative motions and complex geometric shapes, are applied to handle the moving …

Characterization And Enhancement Of Fatigue And Fracture Properties In Thermoplastic Fff Parts Using In-Situ Annealing, Manjarik Mrinal

Mechanical and Aerospace Engineering Dissertations - Archive

Fused filament fabrication (FFF) show high anisotropy and reduced mechanical properties as compared to conventional manufacturing techniques. This happens due to the poor interlaminar bonding between the layers, as a result of premature halt of bond healing process. Previous research works show multiple approaches to improve the bond quality to enhance the mechanical properties of FFF parts, however these are complex and expensive techniques. In this work a novel print head assembly is presented to offer a simple and effective solution by applying a thermal field to the part as it is being printed to preheat the previously deposited layer, …

Internal Pressure Response Of A Human Head Surrogate Model Subject To Variable Impact Loading With Finite Element Analysis, Aaron Ronald Jackson

Mechanical and Aerospace Engineering Theses - Archive

Traumatic brain injury (TBI) from blunt impacts to the head is a major cause of brain disease and dysfunction for thousands of people every year. Each year in the United States approximately 1 million TBI cases occur causing as many as 56,000 deaths and leaving nearly 90,000 individuals with long-term disabilities. Damage resulting from a TBI occurs on a multiscale level including the macroscopic, tissue, and neuron length scale. This research focuses on correlating the macroscopic blunt impact conditions to the internal pressure developed in the coup and countercoup for water and gelatin-filled head models. Two separate 3D printed models …

Synthesis And Characterization Of Graphene-Reinforced Polymer Filaments For Additive Manufacturing, Sean Menezes

Mechanical and Aerospace Engineering Theses - Archive

Fused Deposition Modeling (FDM) is a popular 3D printing process which uses a spool of thermoplastic polymer filament that is melted by the movable extruder printer head onto the bed to generate the required shape. The most used polymer filaments in FDM are Acrylonitrile Butadiene Styrene (ABS) and Poly Lactic Acid (PLA). However, these conventional polymer filaments have lower mechanical strength and are more susceptible to cracking as the cooler parts of the printed part shrink so much that they cause cracks to develop, leading to warping. The current investigation focuses on the synthesis of graphene, synthesis of polymer filaments …

Reverse Engineering To Create High Quality Polymer Parts Using Additive Manufacturing, Gurtej Singh Tarsem Singh Channa

Mechanical and Aerospace Engineering Theses - Archive

Reverse engineering is a process of recreating parts for which the tools no longer exist, reducing the cost of an original part by manufacturing it in-house or redesigning and improving the original part's function. This research demonstrates two methods to reverse engineer a part using Polyworks software, having it printed using an SLS printer and checking the accuracy of the printed part to the original scan. The part is first scanned using a Faro-Arm laser scanner to obtain the point cloud data. The two methods used to recreate and extract the STEP file are: • Exporting NURBS. • Exporting Features …

Development Of The Vehicle Configuration Compendium: A Comprehensive Data-Information-Knowledge System To Aid In High-Speed Vehicle Design, Stenila Simon

Mechanical and Aerospace Engineering Theses - Archive

The conceptual design phase is the most crucial phase in hypersonic vehicle design. Choices made during this phase will have significant impact on the success of the overall project and the feasibility of the end-product. Therefore, it is of utmost importance for the design decision-maker to be adequately informed of past-to-present projects throughout the aerospace community and lessons learned from them. This avoids wasting valuable time and resources for reinventing the wheel. There currently exists no one-stop solution in the aerospace industry to address the issue of lost data, information and knowledge in the field of high-speed vehicle design. The …

Relating Linear And Rotational Accelerations With Internal Pressures Developed Inside Human Head Surrogate Models, Arthur Thomas Koster

Mechanical and Aerospace Engineering Theses - Archive

Traumatic Brain Injury (TBI) is a chronic disease process that is difficult to both detect and treat. TBI can result from blast, kinetic, sonic, and electromagnet energy sources. This research focuses on correlating the bulk acceleration of a human-like head model to the localized internal pressure developed in the coup and contrecoup regions due to variable impact loading. Damage resulting in a TBI occurs on a multiscale level from the macroscale down to the damage of each individual neuron. Obtaining a relationship between bulk acceleration and localized internal pressure will allow for further correlation to the damage done on these …

Investigation Of Heat Transfer Performance Of Double Pipe Counter-Flow Heat Pipe Using Three Fluids Water, Dowtherm, And Water-Based Nanofluid, Alaa Abed Harchan Al Hasseun

Mechanical and Aerospace Engineering Theses - Archive

Heat pipes are two-phase devices, capable of converting a significant amount of energy with low losses. They have been used in several applications such as systems thermal control and cooling. The purpose of the present work is to investigate the thermal performance of a double pipe counterflow against the fluid type. The pipe is divided into three zones including evaporator, adiabatic, and condenser zones. All thermal boundary conditions are defined in terms of heating or cooling temperatures in which the operating temperatures are defined between 303 K to 470 K. using Ansys Fluent, the pipe is analyzed in two-and three-dimensional …

Prediction Of Solder Joint Fatigue Life Of Photonic Package Using ?-? Materials, Ojas Tyagi

Mechanical and Aerospace Engineering Theses - Archive

Fatigue life prediction has become very important factor in reliability of any electronic components to withstand extreme thermal stresses in industrial standard. Hence, photonic packages are widely used in telecommunication and computer applications. The primary focus of this study is to determine the thermal cycles to crack initiation of solder bump used in laser array waferboard for telecommunication applications. This includes GaAs Laser chip on waferboard and Si substrate with pure Indium solder balls in between. Indium has proved higher fatigue life in various experimental studies in the field of reliability and lead-free material. Therefore, a solder ball was designed …

Analysis Of Blood Pressure Waveform For Detection And Diagnosis Of Cardiovascular Anomalies, Atul Shrotriya

Mechanical and Aerospace Engineering Theses - Archive

Cardiovascular diseases are the leading cause of mortalities worldwide as well as in the United States. Early diagnosis and prediction of these diseases is critical to mitigate the risks to the patient. A common method to assess a person’s heart health is through the use of cuff type oscillometric devices placed on the arm of the patient. As the mean pressure in the cuff is increased the blood flow in the brachial artery becomes blocked. When the cuff pressure is reduced the blood starts flowing again; during this cycle, pressure fluctuations in the cuff are measured using a pressure transducer. …

Determination Of Guidance Laws For Uav Systems In Communication Networks Using Collision Cone Theory, Utsav Mudgal

Mechanical and Aerospace Engineering Theses - Archive

Unmanned Aerial Vehicles (UAVs), also commonly known as drones, are used in various applications, including military applications such as surveillance and intelligence-gathering as well as civilian applications such as search and rescue. The use of UAVs to form communication networks is a topic of active research interest. This thesis aims to investigate the development of guidance laws for multiple UAVs to form such communication networks. Toward this end, this thesis employs tools from collision cone theory and incorporates them with parameters used to describe a communication network. Different types of networks are evaluated for use of the guidance laws. Simulation …

Guidance Laws For N-Mobile Agents To Grip A Moving Target, Pranay Gadiya

Mechanical and Aerospace Engineering Theses - Archive

In this thesis, we consider the problem of n mobile agents carrying a gripper, with the objective of gripping a moving circular target. The target may move with constant velocity, or even maneuver. We develop guidance laws by which the agents can first cage the target and subsequently grip it. These guidance laws are developed based on a collision cone framework, using which the mobile agents cooperatively steer their velocity vectors in an appropriate fashion to meet their objective. It is assumed that each of the mobile agents are equipped with a lidar sensor, using which they obtain the range …

Buckling Load Optimization Of Variable Stiffness Composite Plate Using Fem And Semi-Analytical Method, Jeegar Vallabhbhai Patel

Mechanical and Aerospace Engineering Theses - Archive

The advent of new composite manufacturing techniques like Automated Fiber Placement (AFP) offers greater flexibility in structural designs by allowing curvilinear fiber paths. Hence, it is now possible to change laminate stiffness locally, thereby enabling Variable Stiffness (VS) composite structures. Such structures demonstrate superior buckling performance over traditional constant stiffness structures. However, obtaining the optimum fiber paths to improve buckling performance remains an open area of research due to the complexity of determining such fiber paths. This research investigated two approaches for optimizing fiber paths; First, a Finite Element Method (FEM) approach that utilizes linear shape functions to interpolate local …

A Modular Platform For Intrusive Diagnostics And Tps Testing In The Onr-Uta Arc-Jet Facility, Blake Anthony Hamilton

Mechanical and Aerospace Engineering Theses - Archive

This work presents an approach to the design, and successful experimental implementation, of a modular platform for intrusive diagnostics and TPS testing in the ONR-UTA Arc-Heated Wind Tunnel "Leste" Facility. The harsh conditions typical of arc-jet facilities (hypersonic, high-enthalpy, chemically-reacting, continuous flows) present a challenge to the design of insertion platforms. In this work a detailed analysis of the aerothermal loads is used to aid in the design process. Specific design points for this modular platform and its ancillary instrumentation have been identified. Based on this design approach, a modular platform for intrusive diagnostics and TPS testing has been developed. …

Theoretical Prediction Of Mechanical Behavior Of Regular And Chiral Honeycombs Based On Loading Of Single Cell., Sai Krishna K. Pinnamaneni

Mechanical and Aerospace Engineering Dissertations - Archive

Cellular solids are both naturally occurring and man-made materials depending on the characteristic length or Stochastic manner, these materials exhibit a low-relative density usually 30% than the constituent solid material. Low-density cellular solids have been demonstrating superior mechanical properties in various applications from marine to aerospace and lightweight sandwich structures, which has intrigued in development of novel structured materials. Cellular solids offer great design flexibility ashowows how for the targeted geometric for the application-based industry. These materials are used in sandwich structures and come in the shape of hexagonal. An additional aspect of determining the properties and behavior is by …

Multi-Parametric And Multi-Objective Optimization Of Heatsinks For Forced And Natural Convection Based Single-Phase Immersion Cooling Of Server, Tushar Rohidas Wagh

Mechanical and Aerospace Engineering Theses - Archive

An increase in utility of internet-based services, cloud computing and greater performance demands due to rising AI and ML applications have led to a steep growth in GPU and CPU thermal design power. Efficient thermal management of these processors has become a bottleneck in performance enhancement and corresponding power densification of these components. Furthermore, increased pressure on data center owners to reduce power demands and move towards green computing has exacerbated the data center cooling challenges. Single-phase immersion cooling allows data center owners to not only dissipate the increasing heat fluxes efficiently but can also potentially improve equipment reliability as …

A Framework For The Design And Characterization Of Advanced Gaskets, Sannmit Shinde

Electronic Theses and Dissertations, 2020-2023

Most industrial manufacturing or processing plants use bolted connections between pipes that transfer media from one location to another. Gaskets are often used to seal these systems as they offer elevated levels of leak mitigation; however, despite their nearly universal usage, the current understanding of gasket mechanics at the meso-scale is still limited. Contemporary gaskets feature viscoelastic materials, fillers, textures, and are fabricated at various thicknesses. They are used in a wide range of thermal, mechanical, chemical, and temporal conditions. The current work characterizes polytetrafluoroethylene (PTFE) gaskets made with several different filler materials and having vastly different geometries. The chemically …

Gaylord Produce Removal Machine, Marcus Takashi Hirose Lee, Jacob Michael Perlman, Carissa Abigail Kamm, Mark Misao Loera

Mechanical Engineering

This Final Design Review Report outlines the senior design project that began Winter Quarter of 2021 at California Polytechnic State University. Our team consists of three mechanical engineers and a general engineer, working together to design, build, and test a product for Alameda County Food Bank. The goal of the final product is to relieve volunteers and employees of tedious manual labor and increase efficiency during the removal of produce from large Gaylord containers. This document describes background research, the objectives of the project, chosen concept design, analysis and initial prototyping of said concept, the final design, and verification prototype …

Collective Motion In Pelotons And Fish Schools: Observation And Modeling, Syed Rafid Rahman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years there has been a sharp increase in deriving inspiration from nature for engineering applications. However there has been lack of high-resolution data from which insights into collective behavior can be drawn and models can be validated. In this imaging based thesis, data from high-speed, overhead cameras, and GPS tracking are used to collect position and sensory data for large groups of 40 or more members. These data helps us understand how different members (fish, cyclists) of a group interact with each other in collective motion. The focus of this work is to find how individual behavior leads …

Impacts In Fluids: Forces, Scaling Laws And Bouncing Modes In Projectile Impacts On Water Pools And Droplets, Rafsan Rabbi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Projectile impacts in quiescent water pool are synonymous with intriguing splash phenomena and rich underwater physics. Depending on the material property, geometry and surface conditions of the impacting projectiles coupled with the geometric properties of the water pool (e.g., depth, width etc.), contrasting events like sub-surface cavity formation or bouncing of macro-droplets unfolds over millimetric timescales.

In this dissertation, I present four different studies that look at different aspects of impact events with the help of high-speed imaging techniques and implementation of other sensory data acquisition instruments. Firstly, I look at the force of impact associated with projectile water entry …

Towards Automation Of Aluminum Cell Ramming Process, Maryam Salem Abdelfattah Mohamed Alkaabi

Theses

Newly installed cathode blocks in an aluminium reduction cell, expand due to a rapid increase of temperature when passing a high current at the start-up of the cell. High thermal stresses may result if cathode blocks are lined without gaps, and this can lead to cracking of the cathodes and failure of the cell. On the other hand, leaving gaps would cause failure due to molten metal infiltration in the gaps. To overcome these problems carbon-based ramming material is used to fill these gaps. Currently ‘Filling’ is carried out manually or partially automated, but this needs to be fully automated …

Minimization Of The Weld Distortion By Weld Sequence Optimization Using Artificial Intelligence, Jeyaganesh Devaraj

Theses

The application of dissimilar metal welding processes is increasing nowadays in the automobile, aerospace, marine industry as they not only serve for joint welding for different metals but also assist in repairing and reworking in a simplified manner. Study on optimization of weld parameter to weld a structure is important to have control over the distortion, mass deposition, tensile strength, etc. The present research reports the development and implementation of the Genetic algorithm integrated Artificial Neural Network (GANN) based weld sequence optimization for reducing deformation of dissimilar metal joining using the hot-encode technique. Gas Metal Arc Welding (GMAW) is used …

Frequency Domain Measurements Of Melt Pool Recoil Force Using Modal Analysis, Tristan Cullom, Cody Lough, Nicholas Altese, Douglas A. Bristow, Robert G. Landers, Ben Brown, For Full List Of Authors, See Publisher's Website.

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Recoil pressure is a critical factor affecting the melt pool dynamics during Laser Powder Bed Fusion (LPBF) processes. Recoil pressure depresses the melt pool. When the recoil pressure is low, thermal conduction and capillary forces may be inadequate to provide proper fusion between layers. However, excessive recoil pressure can produce a keyhole inside the melt pool, which is associated with gas porosity. Direct recoil pressure measurements are challenging because it is localized over an area proportionate to the laser spot size producing a force in the mN range. This paper reports a vibration-based approach to quantify the recoil force exerted …

2d Layered Sip As Anisotropic Nonlinear Optical Material, Huseyin Sar, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Two-dimensional (2D) material of silicon phosphide (SiP) has recently been shown as a promising optical material with large band gap, fast photoresponse and strong anisotropy. However, the nonlinear optical properties of 2D SiP have not been investigated yet. Here, the thickness-dependent in-plane anisotropic third-harmonic generation (THG) from the mechanically exfoliated 2D layered SiP flakes is reported. The crystal orientation of the SiP flake is determined by the angle-resolved polarized Raman spectroscopy. The angular dependence of the THG emission with respect to the incident linear polarization is found to be strongly anisotropic with the two-fold polarization dependence pattern. Furthermore, the effect …

Naturally Occurring Layered Mineral Franckeite With Anisotropic Raman Scattering And Third-Harmonic Generation Responses, Ravi P. N. Tripathi, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Vertically stacked van der Waals (vdW) heterostructures have introduced a unique way to engineer optical and electronic responses in multifunctional photonic and quantum devices. However, the technical challenges associated with the artificially fabricated vertical heterostructures have emerged as a bottleneck to restrict their proficient utilization, which emphasizes the necessity of exploring naturally occurring vdW heterostructures. As one type of naturally occurring vdW heterostructures, franckeite has recently attracted significant interest in optoelectronic applications, but the understanding of light-matter interactions in such layered mineral is still very limited especially in the nonlinear optical regime. Herein, the anisotropic Raman scattering and third-harmonic generation …

Anisotropic Optical Responses Of Layered Thallium Arsenic Sulfosalt Gillulyite, Ravi P. N. Tripathi, Jie Gao, Xiaodong Yang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Multi-element two-dimensional (2D) materials hold great promise in the context of tailoring the physical and chemical properties of the materials via stoichiometric engineering. However, the rational and controllable synthesis of complex 2D materials remains a challenge. Herein, we demonstrate the preparation of large-area thin quaternary 2D material flakes via mechanical exfoliation from a naturally occurring bulk crystal named gillulyite. Furthermore, the anisotropic linear and nonlinear optical properties including anisotropic Raman scattering, linear dichroism, and anisotropic third-harmonic generation (THG) of the exfoliated gillulyite flakes are investigated. The observed highly anisotropic optical properties originate from the reduced in-plane crystal symmetry. Additionally, the …

Polarization-Dependent Optical Responses In Natural 2d Layered Mineral Teallite, Ravi P. N. Tripathi, Xiaodong Yang, Jie Gao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Multi-element layered materials enable the use of stoichiometric variation to engineer their optical responses at subwavelength scale. In this regard, naturally occurring van der Waals minerals allow us to harness a wide range of chemical compositions, crystal structures and lattice symmetries for layered materials under atomically thin limit. Recently, one type of naturally occurring sulfide mineral, ternary teallite has attained significant interest in the context of thermoelectric, optoelectronic, and photovoltaic applications, but understanding of light-matter interactions in such ternary teallite crystals is scarcely available. Herein, polarization-dependent linear and nonlinear optical responses in mechanically exfoliated teallite crystals are investigated including anisotropic …

Impact Of Surface And Pore Characteristics On Fatigue Life Of Laser Powder Bed Fusion Ti–6al–4v Alloy Described By Neural Network Models, Seunghyun Moon, Ruimin Ma, Ross Attardo, Charles Tomonto, Mark Nordin, Paul Wheelock, Michael Glavicic, Maxwell Layman, Richard Billo, Tengfei Luo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this study, the effects of surface roughness and pore characteristics on fatigue lives of laser powder bed fusion (LPBF) Ti–6Al–4V parts were investigated. The 197 fatigue bars were printed using the same laser power but with varied scanning speeds. These actions led to variations in the geometries of microscale pores, and such variations were characterized using micro-computed tomography. To generate differences in surface roughness in fatigue bars, half of the samples were grit-blasted and the other half were machined. Fatigue behaviors were analyzed with respect to surface roughness and statistics of the pores. For the grit-blasted samples, the contour …